Air borne artificial horizon



July 13, 1937. LMFQCARTER El AL 2,086,897

7 AIR BORNE ARTIFICIAL HORIZON ori in l; Filed May 14, 1955 2 Sheets-Sheet 1 i'i i g W INVENTORS 6 z eficarzes flarhmerfi 0 7 THE/R ATTRNEY.

y 3 L. F. CARTER ET AL 2,036,897

AIR BORNE ARTIFICIAL HORIZON I ori inal Filed May 14, 1935 2 sheets-sheet 2 W9 Jig; 5'

1 AINVENTORS [esljefiarlefi Narhrnerfiflaies Patent ed July 13. 1937 UNITED STATES PATENT OFFICE,

.' l v 2,086,897 V 7 Am BORNE ARTIFICIAL- HORIZON Leslie E. Carter, Leonia, N. J., and Mortimer F. Bates, Brooklyn, N. Y.,.assignors to Sperry Gyroscope Company, Inc., Brooklyn, N. Y., a corporation of New York Application May 14, 1935, Serial No. 21,328 Renewed December 16, 1936 Claims.

This invention relates to air borne gyroscopic instruments, especially to gyroscopic artificial horizons or gyro verticals. In such instruments 7 there are'usually four or five sets of bearings, all

of which are subject to friction and wear and consequently give rise to uncertain performance. One object of the present invention is to so design and construct a gyroscopic instrument of this type that the major portion, if not all, of said bearings are of the air borne or air floated type so that friction is reduced to a minimum,'the weight reduced and the design simplified.

Another object of the invention is to design a gyroscopic artificial horizon for airplanes which can be used after complex airplane maneuvers or stunting, without resetting.

Referring to the drawings showing one form our invention may assume,

Fig. l is a face view of our artificial horizon as it appears from the front of the instrument Fig. 3 is a transverse section of the inner porv tion of the device on line 33 in Fig. 2.

through a channel I in, the pivot stud 8 and.

Fig. 4 is a transverse section on line 4-4 in Fig. 2, looking in the direction of the arrows.

Fig. 5 is a horizontal section of the gyro rotor, showing the spinning jets.

Fig. 6 is "a detached front elevation of thevertical ring employed in the gyroscope.

Fig. 7 is a plan view, partly in section, of a modified form of gyroscope constructed according to our invention.

tinuously exhausted through threaded opening 2 by a suitable pump or Venturi tube (not shown) Said casing is shown as provided at its front with a curved window 3 through which the movable indicating element on the instrument is visible. The gyroscopicv element is shown as mounted for-oscillation about a. transverse horizontal axis 4-4 by suitable bearings. which may 'be'of the airborne type, as are the other bearthence into a circular channel Sin 9. split ring III which surrounds the gyroscope and which normally lies in a vertical plane. Said ring has a substantially semicircular cross'section and of which lies preferably in the plane of the spin axis of the rotor l6 and which gives the gyroscope freedom about a horizontal axis at right angles to the axis 44 and to the spin axis. Air is supplied between said surfaces from channel 9 in the ring I 0', and part of said air passes through apertures l4 in 'said casing and through bores I! in interior button'l5 secured therein to supply an air film to the rotor bearings providing the normally vertical spin axis. The bearings are shown as provided by said buttons l 5 and cooperating concavities l8 in the gyro rotor it, between which an air flow is maintained. The

airis shown as passing down through aperture ii in the upper button I5, part of it escaping between said button and the upper concavity l8 in the gyro rotor. Another portion of said air passes into the center of the rotor through center bore' 50 and radially outwardly through bores l9,

whence it is directed tangentially in the form of jets 20 to spin the rotor.

The gyroscopic system is preferably supported in neutral equilibrium within the casing and the erection obtained by means of an auxiliary pendulum controlling differential air torques about a horizontal axis at right angles to. the angle of inclination. Preferably said auxiliary pendulum is also air supported, as by causing another portion of the air to pass down through the center bore 22 in said concave lower bearing and thence outwardly between a concavity formed in the casing and the button 25 formed onsaid small pendulum 26 which acts to control the erectin force on the gyroscope. 'Air also comes up from below through a concave bearing block 21, passing between said block and the lower button 28 forming a part of the pendulum 26, by means of which'the pendulum is floated. While buttons 24 and 28 have difierent radii of curvature, they preferably have the same center of curvature,

so that the member 26'is universally mounted or' chamber 29 by ring 52, whence the air is directed at right angles to the inclination and outside of the gyro casing through channels 32 and short pipe 33 so as not to disturb the gyroscope. When the gyro casing becomes inclined with respect to the small pendulum 26, the balance of the air flow through the passages 21 and 33 is disturbed and a torque exerted at right angles to the inclination bythe fact that the tubes 33 extend at right angles to the inclination of the pendulum. This operates directly to restore the gyroscope to the vertical.

To indicate the horizon, a miniature airplane 34 may be affixed-to the front face 3 and a horizon bar or other index member 35 may be painted on or secured to spherical shells 36, 36 secured to the gyro casing. Preferably such a bar is painted on both the front and back shells 36 and 36' so that the instrument will be read correctly no matter which face is toward the window and regardless of somersaulting. Said shells may also have a normally vertical index 31 readable on fixed annular graduations 38 to show the angle of bank. The dotted line position shows how the horizon bar 35' would appear on a steep bank and slight downward pitch, while the vertical index would appear as shown at 31 (Fig. 1).

We are aware that gyroscopic artificial horizons have been proposed which may be read from either side, such as shown in the patent to Carlson and Narvesen, No. 1,939,825, dated December 19, 19 3. In such a device, however, it is difilcult to pro 'de a hor' on member on account of the fact that al ring lies between the gyro casing and the front window. It is therefore necessary to make a complicated forward pivot and carry the trunnion of the casing through the gimbal ring. According to our present invention, however, the vertical ring l0 replaces the ordinary gimbal of the prior art and, since the said ring [0 is circumferential and lies in a vertical plane, it does not interfere with the full view of the movements of the gyro casing as indicated by the bars 35 secured to the masks 36, 35' on both sides of the gyroscope. Our invention is especially adapted, therefore, to this type of horizon, designed for permitting somersaulting and looping the loop, since there are no parts to strike under these conditions. Preferably, as shown in the drawings, all three perpendicular axes of freedom of the gyroscope (i. e., the normally vertical spin axis of the rotor, the normally horizontal axis about which ring l0 turns and the second horizontal axis 8-8) intersect at the center of the rotor, so that one indicator 35 may be usedto show the true angles of both pitch and roll.

It is obvious that the convex and concave parts may be interchanged at will. Fig. 7 illustrates a modification in which the vertical ring 4| is concave in cross section on its inner surface 42 and the gyro casing is provided with an annular ridge 43 convex in cross section having an annular channel 9' for the air.

As many changes could be made in the above construction and many apparently widely difierent embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having described our invention, what we claim and desire to obtain by Letters Patent is:

1. In an air borne gyroscope, a rotor, a casing in which said rotor is journalled for spinning about an axis, a ring wi n which said casing ismounted for oscillation, said ring and casing having complementary in-teri'itting curved surfaces extending circumferentially of said ring and the central plane of said ring lying in the same plane as said rotor spin axis, and means for supplying an air flow between said surfaces to float said casing within said ring for oscillation about an axis at right angles to said central plane and to the rotor spin axis.

2. In an air borne gyroscope, a rotor, a casing in which said rotor is journalled for spinning about an axis, a ring within which said casing is mounted for oscillation about an axis at right angles to the rotor spin axis, said ring and casing having complementary interfitting curved surfaces extending circumferentially of said ring,

. and means for supplying an air flow between said surfaces to float said casing within said ring.

3. In an air borne artificial horizon, a rotor, a casing therefor, spaced spherical air bearings between said rotor and casing mounting said rotor for spinning about a normally vertical axis, a pendulous member floated between air hearings in said casing, there being ports leading without said casing adapted to be differentially covered by said member on relative tilting of said member and said casing and to exert torques on said casing about axes at right angles to the axes about which the tilt occurs, and means for supplying air flow between said bearings and through said ports.

4. In a. gyroscope, a universally mounted cas- -ing, means for causing continuous air flow from of upon relative tilting of said casing and member, said member having upper and lower buttons thereon of different radii but a common center of curvature, cooperating concavities formed within said casing, the aforesaid air flow passing in part between said buttons and concavities.

5. An air driven air supported artificial horizon for aircraft, comprising a normally horizontal rotor, a rotor bearing casing, upper and lower spherical air bearings for the rotor in said casing, an outer ring, said ring and casing having interfitting curved surfaces circumferentially of the ring to form a single circumferential air bearing, and air erecting means on said casing.

6 In a gyroscope, a rotor member, a rotor bearing frame member,'a pair of spaced bearings between said members comprising a pair of spherical projections on one of said members, there being complementary cup shaped sockets in the other of said two members, and registering apertures through said cups and projections for leading air under pressure between the bearing surfaces so formed, the rotor having an axial H 2,086,897 tons thereon, there being cooperating concavities" in said casing for universally mounting said pendulous member, a portion of the air passing through said rotor also flowing between at least one of said buttons and its supporting concavity.

7. A gyroscopic artificial horizon for aircraft comprising a rotor, a rotor bearing casing in which said rotor is mounted for spinning about a normally vertical axis, a normally vertical ring surrounding said casing and slidably supporting the same for turning about the normally horizontal axis of the ring, an outer casing in which said ring is mounted for oscillation about a hori-. zontal axis perpendicular to the axis of said ring, all three of said axes intersecting at a common point at the center of the rotor, and said rotor bearing casing having single means thereon for indicating both pitch and bank of the aircraft, visible fromthe front of said casing.

8. A gyroscopic artificial horizon:- for aircraft comprising a rotor, a rotor bearing casing, a normally vertical ring surrounding said casing and having an inner periphery of curved cross section,- sa'id casing having its exterior of a complementary curved section and slidably' fitting the inner periphery of-said ring, means for supplying air iiow between said ring and casing thereby slidably supporting the casing for turning about the normally horizontal axis normal to the plane ofthe ring, an outer casing in which said ring is mounted for oscillation about a horizontal axis perpendicular to the said first mentioned axis of said ring. said rotor bearing cas- I casing, means for supplying air films to; float said memberbetween said cups, there being ports 3 ing having single means thereon for indicating both pitchand bank of the aircraft, visible from the front of said casing.

-9. In an artificial horizon, a universally mounted casing, means for causing continuous air flow 5 between the interior and the exterior of said casing, means for spinning the horizon rotor by said air flow, a plurality of ports'in said casing lying in the same horizontal plane, a pendulous member having an edge lying adjacent said ports to vary the relative opening thereofupon relative tilting of said casing and member, said member having upper and lower buttons thereon of different radius but a common center of curvature, cooperating concavities formed within said, 15 casing, the aforesaid air flow passing in part between said buttons and concavities to float said pendulous member on air bearings.

10. In an air borne gyroscope having three'degrees of-freedom, 'a universally mounted rotor bearing casing, a pendulous erecting or clamping device therein comprising a pendulous member having upper and lower spherical. surfaces, there being cooperating upper and lower cups in said in said casing from which said air escapes, said pendulum diflerentially uncovering said ports upon relative inclination of said casing and pendulum.

LESLIE F. CARTER. MORTIMER F. BATES. 

